1. Field of the Invention
This invention relates generally to brake control valve devices for railway cars and more particularly to a pipe bracket portion of said brake control valve devices having a plurality of access ports for directly accessing fluid lines and determining the pressures thereof.
2. Description of the Prior Art
Typical freight control valves such as the ABD, ABDW, DB-60 and ABDX control valves include a pipe bracket portion having a service portion and an emergency portion mounted on opposite sides or faces of the pipe bracket. Such a typical control valve assembly is shown in prior art diagrammatic FIG. 1. One such prior art pipe bracket is known as the type AB pipe bracket. Typically, a second side, the rear, of the pipe bracket portion has a number of locations for connecting the pipe bracket portion to the piping of the freight car. These rear connections typically include connections to the brake pipe, the brake cylinder retaining valve, the brake cylinder, the emergency reservoir and the auxiliary reservoir. The pipe bracket connection to the pneumatic piping permits the pipe bracket to provide the necessary communication of fluid pressures to both the service portion and emergency portions in addition to the brake cylinder and reservoir.
Most type AB pipe brackets only have connections to pipe lines on their rear surface. However, some older AB pipe brackets manufactured prior to 1975 may have included a pipe flange pad for a brake cylinder release and/or a pipe flange pad for the number 11 port. This number 11 port could be used as a source of auxiliary air to operate pneumatic devices. Port 11 is shown in the Westinghouse Air Brake Brochure No. 5062 titled "The AB Freight Car Air Brake Equipment With AB Control Valve" dated December 1975. Specifically, the AB control valve shown on page 2 shows a cover bolted over port 11 with two bolts on the front surface of the pipe bracket portion. Port 11 is connected to the brake pipe in such older style AB pipe brackets. Further, some older style AB pipe brackets may in addition to port 11 include a flange pad for a brake cylinder release valve with ports to the brake cylinder and exhaust. Such valves were known as type QR, QRR or QRB; and had two or three ports (in addition to the number 11 port) on the front of the pipe bracket. The pipe brackets with four ports included two ports to the brake cylinder air and one port to the retaining valve, and a number 11 port to the brake pipe.
It is sometimes necessary to tap into the fluid lines for the purpose of obtaining pressure measurements of the fluid within the freight car piping. However, one must access the area behind the pipe bracket, the second side, which contains the connections of the pipe bracket to the piping of the freight car.
Accessing the area behind the pipe bracket is frequently difficult depending upon the placement of the brake control valve on the freight car. In addition, the connections between the pipe bracket and freight car piping would then be broken to allow monitoring of the pressures.